Taking risk on a number which is more than ten years old and that too based on bluffs of ChoRCom is no less than playing a BlueWhale challenge game, imho. Just port out from them and retain that decade old number. RCom will say anything for controlling the dead rolling of their shares.
Just remember that
(1) They said good bye to their employees.
(2) CC (Tech Mahindra) already said good bye to them (from Sep) due to non-payment of dues for years.
(3) Even they said, 4G data card business to ENTERPRISE only, with no CustomerCare support, no Retail counters & no own network infra (using Jio's only).
(4) They will continue that till profitable -- Why others should choose Rcom over Jio???
So I repeat, if your number is very important, just escape from RCom as early as possible, imho.